This section lists SIP Common IP Attributes transparency flags details.
Prior to release 7.1, when the To-Header Transparency flag is set, the Request-URI is sent transparently even when the globalization flag of the Number Globalization Profile is enabled. In this case, the To-Header Transparency does not send the called number in the Request-URI locally.
Henceforth, the SBC supports globalizing the Request-URI by enabling globalization for the called number and enabling the To-Header Transparency flag. Thus, the Request-URI called number is not transmitted transparently to the egress leg (To-Header transparency flag will not affect Request-URI globalization). Note that Request-URI globalization is independent of the To-Header Transparency. This functionality applies to all scenarios where To-Header transparency is enabled, such as:
% set profiles signaling ipSignalingProfile <profile_name> commonIpAttributes transparencyFlags acceptContactHeader <disable | enable> acceptHeader <disable | enable> acceptLanguageHeader <disable | enable> alertInformationHeader <disable | enable> authcodeHeaders <disable | enable> callInfoHeader <disable | enable> contactHeader <disable | enable> errorInfo <disable | enable> externalBody <disable | enable> fromHeader <disable | enable> geolocation <disable | enable> geolocationError <disable | enable> geolocationRouting <disable | enable> historyInfo <disable | enable> maxForwardsHeader <disable | enable> messageExternalBody <disable | enable> mwiBody <disable | enable> pAccessNetworkInfoHeader <disable | enable> pCalledPartyID <disable | enable> pChargingVectorHeader <disable | enable> pEarlyMedia <disable | enable> pVisitedNetworkIDHeader <disable | enable> passCompleteContactHeader <disable | enable> pathHeader <disable | enable> pidfBody <disable | enable> pidfDiffBody <disable | enable> qsigBody <disable | enable> reasonHeader <disable | enable> referredByHeader <disable | enable> requestURI <disable | enable> resourceListBody <disable | enable> resourcePriorityOptionTag <disable | enable> rlmiBody <disable | enable> routeHeader <disable | enable> serverHeader <disable | enable> serviceRouteHeader <disable | enable> simpleFilterBody <disable | enable> sipBody <disable | enable> sipfragBody <disable | enable> toHeader <disable | enable> toneBody <disable | enable> unknownBody <disable | enable> unknownHeader <disable | enable> userAgentHeader <disable | enable> userToUserHeader <disable | enable> viaHeader <disable | enable> warningHeader <disable | enable> watcherInfoBody <disable | enable>
For a list of SIP headers that cannot be controlled using transparency flags in relay scenarios, refer to IPSP Transparency Flags.
The Transparency Profile is the recommended method of configuring transparency on the SBC Core for new deployments as well as when applying additional transparency configurations to existing deployments. Do not use IP Signaling Profile flags in these scenarios because the flags will be retired in upcoming releases.
Refer to the SBC SIP Transparency Implementation Guide for additional information.
From system-level prompt, use following command to view IP signaling profile flags for DEFAULT_SIP profile in table format.
> show table profiles signaling ipSignalingProfile DEFAULT_SIP egressIpAttributes flags bgcfTargetSchemeTransparency disable; convertInactiveToSendrecv disable; disable2806Compliance disable; disableOptionalRegisterParameters disable; map181Or182MessageTo183 disable; mapContractorNumberInPSigInfoHeader disable; suppressUnregister disable; ttcIsupMapping disable; useCalledPartyInRequestUri disable; useColonInSdpMediaTypeParameter disable; validateIsubAddress disable; qosBasedRouting disable;
Example1:
In the following call flow, the Modify Offers (in green) are suppressed if the Minimize Relaying Of Media Changes From Other Call Leg flag is enabled:
Ingress Peer |
| SBC |
| Egress Peer |
G711U | -> | SBC offers G711U as pass-through codec and G729A as a transcode option by reserving a DSP channel | -> | G711U,G729A |
G711U | <- | SBC releases the DSP channel resulting in a G711U pass-thru call | <- | G711U |
|
| Receive capabilities of SBC have changed as a codec G729A was removed and the DSP channel de-allocated. | -> | G711U |
|
|
| <- | G711U |
Example 2:
The messages (in green) can be suppressed if the Disable Media Lock Down field is enabled.
Ingress Peer |
| SBC |
| Egress Peer |
G711U | -> | SBC offers G711U as pass-through codec and G729A as a transcode option by reserving a DSP channel | -> | G711U,G729A |
G711U | <- | SBC releases the DSP channel resulting in a G711U pass-thru call | <- | G711U,G729A |
|
| Receive capabilities of SBC have changed as a codec G729A was removed and the DSP channel de-allocated. | -> | G711U |
|
|
| <- | G711U |
Ingress Peer |
| SBC |
| Egress Peer |
G711U | -> | SBC offers G711U as pass-through codec and G729A,G726 as transcode options by reserving a DSP channel | -> | G711U,G729A,G726 |
G711U | <- | Transcode G711-G729A call. Egress codec is locked down to G729A | <- | G729A,G726 |
|
| Receive capabilities of SBC have changed to G729A due to transcode. | -> | G729A |
|
|
| <- | G729A |
Example 3:
Scenario in which Disable Media Lockdown field can not suppress the media lock down messages (in green).
The codecs configured at Egress route PSP are G711U, G726, G729A with HRP disabled.
Ingress Peer |
| SBC |
| Egress Peer |
G711U | -> | SBC offers G711U as pass-through codec and G726,G729A as transcode options by reserving a DSP channel | -> | G711U,G726,G729A |
G711U | <- | Transcode G711-G726 call. Egress codec is locked down to G726 | <- | G729A,G726 |
|
| Receive capabilities of SBC have changed to G726 ( i.e. HRP is disabled). Since, the codec selected by SBC is different from Peer’s preferred codec (G729), though the flag DML is enabled SBC sends a Modify Offer to lockdown to G726. | -> | G726 |
|
|
| <- | G726 |
Example1:
The re-INVITEs (in green) are suppressed if the Minimize Relaying Of Media Changes From Other Call Leg flag is enabled.
Ingress Peer |
| SBC |
| Egress Peer |
G711U | -> | SBC offers G711U as pass-through codec and G729A as a transcode option by reserving a DSP channel | -> | G711U,G729A |
G711U | <- | SBC releases the DSP channel resulting in a G711U pass-thru call | <- | G711U |
|
| Receive capabilities of SBC have changed as a codec G729A was removed; send Modify Offer to Peer to advertise the latest set of capabilities | -> | G711U |
|
|
| <- | G711U |
Example2:
SBC suppresses a Modify Offer from the ingress peer. The offer changes the maxptime from 10 to 20ms. An increase in maxptime can be suppressed – a device that advertises a maxptime of 20ms can also receive 10ms packets.
Ingress Peer |
| SBC |
| Egress Peer |
G711U 10ms | -> |
| -> | G711U 10ms |
G711U | <- |
| <- | G711U |
Re-INVITE (G711U 20ms) | -> | Suppress the re-INVITE if minimize media is enabled and respond to ingress peer; else forward the re-INVITE to egress | -> | G711U 20ms |
G711U | <- |
| <- | G711U |
Conversely, irrespective of the state of the Minimize Relaying Of Media Changes From Other Call Leg flag All field cannot suppress a change of maxptime from 20ms to 10ms.
Ingress Peer |
| SBC |
| Egress Peer |
G711U 20ms | -> |
| -> | G711U 20ms |
G711U | <- |
| <- | G711U |
Re-INVITE (G711U 10ms) | -> |
| -> | G711U,10ms |
G711U | <- |
| <- | G711U |
Example3:
A change of data-path-mode from sendrecv to sendonly ( HOLD request) can also be suppressable. The rational is that SBC can always ignore the media received from the peer and continue to send it media.
Ingress Peer |
| SBC |
| Egress Peer |
G711U sendrecv | -> |
| <- | G711U sendrecv |
G711U | <- |
| -> | G711U |
Re-INVITE (G711U sendonly) | -> | Suppress the re-INVITE if minimize media is enabled and respond to ingress peer; else forward the re-INVITE to egress | <- | G711U sendonly |
G711U | <- |
| -> | G711U |
Conversely, SBC irrespective of the state of the Minimize Relaying Of Media Changes From Other Call Leg flag, cannot suppress a change of data-path-mode from sendonly to sendrecv.
Ingress Peer |
| SBC |
| Egress Peer |
G711U sendonly | -> |
| -> | G711U sendonly |
G711U | <- |
| <- | G711U |
Re-INVITE (G711U sendrecv) | -> |
| -> | G711U sendrecv |
G711U | <- |
| <- | G711U |
Example1:
When Minimize Relaying Of Media Changes From Other Call Leg
flag is enabled, and when Relay Data Path Mode Change From Other Call Leg
is disabled:
Ingress Peer |
| SBC |
| Egress Peer |
G711U,G729A sendrecv | -> |
| -> | G711U,G729A sendrecv |
G711U | <- |
| <- | G711U |
Re-INVITE (G711U sendonly) | -> | Suppress the re-INVITE and respond to ingress peer. Discard media received from the egress peer |
|
|
G711U | <- |
|
|
|
Example2:
When the Minimize Relaying Of Media Changes From Other Call Leg
flag is enabled, and when Relay Data Path Mode Change From Other Call Leg
is enabled:
Ingress Peer |
| SBC |
| Egress Peer |
G711U,G729A sendrecv | -> |
| -> | G711U,G729A sendrecv |
G711U | <- |
| <- | G711U |
Re-INVITE (G711U sendonly) | -> |
| -> | G711U sendonly |
G711U | <- |
| <- | G711U |